Conventionally, as a method of imparting nanoimprint, optical element or the like with a fine shape, such a method has been formed that the shape is transferred to a glass substrate, plastic substrate, plastic film, etc. using a mold with the fine shape formed beforehand therein (Patent Documents 1 and 2).
Among these techniques are a method of pressing a mold (also referred to as a die or a template) that is an original plate with a pattern of fine grooves, holes, etc. formed therein against a transfer target material and thereby transferring the pattern mechanically, another method of transferring using a thermoplastic resin, still another method of optically transferring using a photo-curing resin, etc. (Patent Document 3). The resolution of the pattern in these methods is determined by fabrication accuracy of the mold. In other words, once the mold is prepared, it is possible to form the fine structure with an inexpensive apparatus. As the mold that is the original plate, known generally are a parallel flat-plate type mold (referred to as a wafer or plate) and a cylindrical (roller) type mold, from their shapes (Patent Document 4, Non-patent Document 1).
As a production process of the parallel flat-plate type mold, there are a method using a semiconductor lithography technique by applying an ultraviolet photo resist, electron beam resist, X-ray resist or the like onto a substrate, then irradiating and exposing the substrate with/to ultraviolet light, electron beams, X-rays or the like to fabricate an original plate of a preferred pattern, and another method of fabricating an original plate through a mask (reticle) with a pattern beforehand rendered therein (Patent Document 5)
Theses methods are very effective methods for forming an extremely fine pattern of about 100 nm on a flat plate. However, since a photoresist using photoreaction is used, it is necessary to expose using a spot smaller than the pattern required in principle so as to form a fine pattern. Accordingly, since a KrF or ArF laser, etc. with short wavelengths is used as an exposure light source, the exposure apparatus is large and the complicated mechanism is required. Further, in the case of using an exposure light source of electron beam, X-ray or the like, since a vacuum is required as an exposure atmosphere, it is necessary to place the original plate in a vacuum chamber. Therefore, it is significantly difficult to increase the original plate size. Meanwhile, to fabricate a large-area mold using these methods, considered is a method of using a step-and-repeat function for connecting small exposure areas to fabricate, but there is a problem in the connection accuracy between patterns (Patent Document 6).
Meanwhile, as a method of fabricating a cylindrical (roller) type mold, two methods have conventionally been adopted. First, there is a method of fabricating a parallel flat-plate original plate once, transferring the shape by electroforming comprised of a thin foil made of nickel or the like, and winding the thin foil around a roller (Patent Document 7). Another method (seamless roller mold) is a fabricating method of directly rendering a mold pattern on a roller by laser processing or mechanical processing (Non-patent Document 2). In the former method, it is necessary to wind a nickel thin-foil mold with an area larger than the area to manufacture, and there is another problem that a seam arises in the winding portion. Meanwhile, in the latter method, once the mold is fabricated, the mold is high in productivity and excellent in volume production, but it is significantly difficult to form a pattern of the submicron (less than 1 μm) size using laser processing or mechanical processing.